After unpacking the last of her belongings, Buffy stops by her mom's bedroom to announce that she's heading outside. Joyce hangs up a Nigerian mask that she got from a friend at her art gallery, then hesitantly gives her daughter permission to go find her friends. Later, in a dark alley, Buffy notices a shadowy figure roaming the alleys. Suspicious, she follows him and accidentally draws his attention by stepping on an aluminum can. The figure spins around and thrusts a stake at her, which Buffy easily blocks. As she grabs the stake out of the man's hands and turns it towards him, she realizes that it's Xander. Before either of them can say much, a vampire appears and attacks the both of them. During the struggle, Buffy hears Cordelia's voice on a walkie-talkie attached to Xander's waist. Soon enough, Cordy, Willow, and Oz arrive on the scene, all decked out with stakes and crosses. Buffy is surprised to see her friends work as a team to get the vampire off of Buffy. One by one, though, they are knocked to the ground by the powerful vampire. Finally, Buffy jumps in and finishes the job, reducing the vampire to a pile of dust. After Buffy greets her bewildered friends, they head over to Giles' apartment. The Watcher is emotionally overcome with joy from seeing his Slayer safe and sound, although he doesn't fully express it until he's alone in his kitchen. In the living room, Buffy avoids discussion topics relating to what she did over the summer. She then makes plans with Willow to meet somewhere the next afternoon.

The next day, Joyce and Buffy visit Principal Snyder in his office. Despite Joyce's protests, Snyder refuses to readmit Buffy back into the school. Afterwards, Joyce drops Buffy off at a coffee shop where she plans to meet Willow. However, Willow never shows up. Buffy heads home, and as she heads towards her front door, a woman steps out. She introduces herself as Pat, a friend of Joyce's at the book club. Inside, Joyce tells Buffy that she invited Giles and her friends over to dinner the following evening. Buffy goes into the basement to get their fancy company plates. There, she finds a stray cat that has been dead for a while. Buffy and Joyce bury it outside. Later that night, after both Buffy and Joyce have fallen asleep, the eyeholes of the mask in Joyce's bedroom begin to glow. As they do so, the stray cat works its way out of the ground as if it had never died.

Overnight, Buffy dreams that she is walking around the Sunnydale High campus. Nobody else is there, except for Angel. She then wakes up and heads to the kitchen. The stray cat reenters the Summers home, shocking both Buffy and Joyce. Giles arrives shortly with a cage to capture the cat and bring it back to the library for further study. After finding the cat in Joyce's bedroom, he notices the Nigerian mask on her wall. He then informs Buffy that she is no longer allowed on school grounds. At the library, Giles studies his demonology text while the rest of the Slayerettes make plans for the dinner that evening. By the end of their discussion, the intimate dinner has become a full-blown party, complete with pot luck snacks and Oz's band. During the discussion, Giles carelessly flips past a page without looking at it. On this page is a picture of the same mask hanging in Joyce's bedroom.

That evening, Pat comes over to visit Joyce. Merely moments after Buffy shuts the door, Oz's band, Dingoes Ate My Baby, arrives. Buffy was not notified in advance that they had planned a huge party, but that's exactly what she gets before long. After wading through dozens of people she's never even met before, Buffy finds Willow near the band. Buffy pulls her over to a quieter area and asks Willow if she's been avoiding her. Willow denies this, then immediately leaves Buffy alone and heads back to where the band is playing. On her way upstairs, Buffy briefly talks to Xander and Cordelia, who are lost in their own world of nonstop smoochies. Buffy then stops outside the kitchen, where Joyce and Pat are talking about having Buffy back home. Buffy overhears her mom talking about how much more difficult it is now that Buffy's home. Unable to take much more animosity from her closest friends and family, Buffy goes up to her bedroom and starts packing her bag again. Meanwhile, Giles finally finds what he's been looking for in his texts: the picture of the Nigerian mask. Horrified by what he reads, he calls the Summers home, but one of the partygoers answers the phone, and the music is too loud for him to fully understand what Giles is saying. Giles gives up and drives towards Buffy's home. On the way, he accidentally hits a man in the middle of the road. Upon getting out and inspecting the body, Giles realizes that this man died long before he ever wandered onto the road. The corpse grabs Giles and shoves him against the car. Giles watches in horror as he sees several more zombies appearing from the shadows. All over town, corpses arise from crime scenes, hospital beds, and even their graves, all with one destination in mind: the Summers household. Giles finally fends off the zombies and gets back in his car.

Willow finds Buffy packing her bag in her bedroom. Not long after they argue over Buffy's decision to run away, Joyce enters the bedroom. Her reaction to seeing Buffy's packed bag is much more heated. Buffy tries to get out of the house, but Joyce stops her right in the middle of the main floor. As everybody gathers around and watches, Joyce drops all her restraints and angrily chews out Buffy for what she did (and didn't do) over the summer. Buffy tries to defend herself, but Xander joins in and offers his own cold remarks. Just as it seems that everybody is against Buffy and her whole world is caving in, the zombies invade the household. They quickly and brutally attack and kill several of the guests, while everybody else runs for their lives. Many try to keep the doors and windows blocked off, while others just panic in general. One of the zombies grabs Pat and drags her off down a hallway. While Buffy, Joyce, Xander, and Willow run upstairs, Oz and Cordelia hide in a downstairs closet. Upstairs, Joyce finds Pat lying flat on the floor. They help her to her feet and into Joyce's bedroom. While the group tries to keep the zombies from forcing the door open, Willow checks Pat's pulse and realizes that she's already dead.

Several moments later, Oz and Cordelia step out of the closet and notice that all of the zombies are now upstairs. They run into Giles, who has just arrived. He explains that the mask contains the power of the zombie demon named Ovu Mobani, or Evil Eye. All the zombies are after it, and whoever puts it on will become the demon. Upstairs, nobody notices Pat as she suddenly gets up. Surprised to see that her friend is alive, Joyce runs over, only to be knocked to the floor by the zombie Pat. As Joyce and Xander look on, Pat puts the mask on, which immediately molds to her face. Pat begins to speak, except it isn't her voice anymore. It is the voice of the demon Ovu Mobani, and the zombies that were previously trying to get into the room are now paralyzed with fear by Mobani's presence. Buffy tries to attack the demon, but it turns its head and flashes a brilliantly white light which stuns Buffy. Unable to move, Buffy takes the powerful blow of the demon hard. The demon then stuns Willow and moves in for the kill, but not before Buffy recovers and pushes Mobani through the second story window, along with herself. After they crash onto her backyard, Buffy tries to avoid the demon's gaze by covering her eyes. Giles tells Oz to warn Buffy that attacking its eyes is the only way to defeat Mobani. Oz runs out and immediately falls victim to Mobani's stun flash. Buffy uses this moment to her advantage and thrusts a shovel directly into the demon's eyes. It cries out in horror, then vanishes, along with all of the other zombies. After everybody regroups inside, nobody can bring themselves to spite Buffy any longer, as she finally embraces Willow after so long.

The next day, Giles visits Principal Snyder's office and threatens to contact state officials if Buffy isn't readmitted. When Snyder doesn't believe his threat, Giles applies a little brute force to get his message across. Later, Buffy and Willow meet at the coffee shop. Willow discusses her experiments with witchcraft. They understand what each other has been feeling during the past few months, and like the true friends that they are, accept it.